CONICET | Buscador de Institutos y Recursos Humanos

Andean structures preserve evidence of previous periods of deformation along the proto-Pacific marginof Gondwana. Particularly, the Southern Precordillera, in the southern Central Andes, presents acombination of different structural domains and a double vergence related to the reactivation of pre-Andean structures. This combination and the superposition of deformational events make it difficult tounderstand the stratigraphic systems and the evolution of the region. This contribution presents detailedinformation about the structures and evolution of the Southern sector of the Precordillera, focusing onthe control exerted by Paleozoic structures over the recent Andean deformation, and the deformationalstyles of this fold-and-thrust belt. Three main structural domains are recognized. The western domain ischaracterized by high-angle back-thrusts that concentrate the highest amount of uplift. The centraldomain is composed of reverse double-vergence faults, and high-angle strike-slip faults. The easterndomain is characterized by pure contractional deformation and only east-verging structures. Fourdeformational events are recorded and analyzed along the Southern Precordillera at 32°30S: (1) anEarly Paleozoic compressional event, (2) a Late Paleozoic compressional event, (3) a Triassic extensionalevent, and (4) the Cenozoic Andean compressional event. Our model for the Cenozoic deformation of theSouthern Precordillera is restricted to three stages of deformation. During the first stage, Paleozoic westvergingfaults are reactivated. The second stage implies reactivation of Paleozoic and Permian-Triassicstructures and the generation of reverse Andean faults. The final stage consists of the generation of NESWAndean thrusts.

enviar mensaje